Sodium channel blockers

ABSTRACT

The present invention relates to compounds represented by formula (I): 
     
       
         
         
             
             
         
       
         
         
           
             in which at least one of R 3  and R 4  is a group represented by formula (A): 
           
         
       
    
     
       
         
         
             
             
         
       
         
         
           
             where the structural variables are defined herein. The compounds are useful for blocking sodium channels.

CONTINUING APPLICATION DATA

This application is a Divisional of application Ser. No. 10/076,551,filed on Feb. 19, 2002, now U.S. Pat. No. 6,858,614. That application isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to sodium channel blockers. The presentinvention also includes a variety of methods of treatment using theseinventive sodium channel blockers.

2. Description of the Background

The mucosal surfaces at the interface between the environment and thebody have evolved a number of “innate defense”, i.e., protectivemechanisms. A principal form of such innate defense is to cleanse thesesurfaces with liquid. Typically, the quantity of the liquid layer on amucosal surface reflects the balance between epithelial liquidsecretion, often reflecting anion (C1⁻ and/or HCO₃ ⁻) secretion coupledwith water (and a cation counter-ion), and epithelial liquid absorption,often reflecting Na⁺ absorption, coupled with water and counter anion(C1⁻ and/or HCO₃ ⁻). Many diseases of mucosal surfaces are caused by toolittle protective liquid on those mucosal surfaces created by animbalance between secretion (too little) and absorption (relatively toomuch). The defective salt transport processes that characterize thesemucosal dysfunctions reside in the epithelial layer of the mucosalsurface.

One approach to replenish the protective liquid layer on mucosalsurfaces is to “re-balance” the system by blocking Na⁺ channel andliquid absorption. The epithelial protein that mediates therate-limiting step of Na⁺ and liquid absorption is the epithelial Na⁺channel (ENaC). ENaC is positioned on the apical surface of theepithelium, i.e. the mucosal surface-environmental interface. Therefore,to inhibit ENaC mediated Na⁺ and liquid absorption, an ENaC blocker ofthe amiloride class (which blocks from the extracellular domain of ENaC)must be delivered to the mucosal surface and, importantly, be maintainedat this site, to achieve therapeutic utility. The present inventiondescribes diseases characterized by too little liquid on mucosalsurfaces and “topical” sodium channel blockers designed to exhibit theincreased potency, reduced mucosal absorption, and slow dissociation(“unbinding” or detachment) from ENaC required for therapy of thesediseases.

Chronic bronchitis (CB), including the most common lethal genetic formof chronic bronchitis, cystic fibrosis (CF), are diseases that reflectthe body's failure to clear mucus normally from the lungs, whichultimately produces chronic airways infection. In the normal lung, theprimary defense against chronic intrapulmonary airways infection(chronic bronchitis) is mediated by the continuous clearance of mucusfrom bronchial airway surfaces. This function in health effectivelyremoves from the lung potentially noxious toxins and pathogens. Recentdata indicate that the initiating problem, i.e., the “basic defect,” inboth CB and CF is the failure to clear mucus from airway surfaces. Thefailure to clear mucus reflects an imbalance between the amount ofliquid and mucin on airway surfaces. This “airway surface liquid” (ASL)is primarily composed of salt and water in proportions similar to plasma(i.e., isotonic). Mucin macromolecules organize into a well defined“mucus layer” which normally traps inhaled bacteria and is transportedout of the lung via the actions of cilia which beat in a watery, lowviscosity solution termed the “periciliary liquid” (PCL). In the diseasestate, there is an imbalance in the quantities of mucus as ASL on airwaysurfaces. This results in a relative reduction in ASL which leads tomucus concentration, reduction in the lubricant activity of the PCL, anda failure to clear mucus via ciliary activity to the mouth. Thereduction in mechanical clearance of mucus from the lung leads tochronic bacterial colonization of mucus adherent to airway surfaces. Itis the chronic retention of bacteria, the failure of local antimicrobialsubstances to kill mucus-entrapped bacteria on a chronic basis, and theconsequent chronic inflammatory responses of the body to this type ofsurface infection, that lead to the syndromes of CB and CF.

The current afflicted population in the U.S. is 12,000,000 patients withthe acquired (primarily from cigarette smoke exposure) form of chronicbronchitis and approximately 30,000 patients with the genetic form,cystic fibrosis. Approximately equal numbers of both populations arepresent in Europe. In Asia, there is little CF but the incidence of CBis high and, like the rest of the world, is increasing.

There is currently a large, unmet medical need for products thatspecifically treat CB and CF at the level of the basic defect that causethese diseases. The current therapies for chronic bronchitis and cysticfibrosis focus on treating the symptoms and/or the late effects of thesediseases. Thus, for chronic bronchitis, β-agonists, inhaled steroids,anti-cholinergic agents, and oral theophyllines and phosphodiesteraseinhibitors are all in development. However, none of these drugs treateffectively the fundamental problem of the failure to clear mucus fromthe lung. Similarly, in cystic fibrosis, the same spectrum ofpharmacologic agents is used. These strategies have been complemented bymore recent strategies designed to clear the CF lung of the DNA(“Pulmozyme”; Genentech) that has been deposited in the lung byneutrophils that have futilely attempted to kill the bacteria that growin adherent mucus masses and through the use of inhaled antibiotics(“TOBI”) designed to augment the lungs' own killing mechanisms to ridthe adherent mucus plaques of bacteria. A general principle of the bodyis that if the initiating lesion is not treated, in this case mucusretention/obstruction, bacterial infections became chronic andincreasingly refractory to antimicrobial therapy. Thus, a major unmettherapeutic need for both CB and CF lung diseases is an effective meansof re-hydrating airway mucus (i.e., restoring/expanding the volume ofthe ASL) and promoting its clearance, with bacteria, from the lung.

R. C. Boucher, in U.S. Pat. No. 6,264,975, describes the use ofpyrazinoylguanidine sodium channel blockers for hydrating mucosalsurfaces. These compounds, typified by the well-known diureticsamiloride, benzamil, and phenamil, are effective. However, thesecompounds suffer from the significant disadvantage that they are (1)relatively impotent, which is important because the mass of drug thatcan be inhaled by the lung is limited; (2) rapidly absorbed, whichlimits the half-life of the drug on the mucosal surface; and (3) arefreely dissociable from ENaC. The sum of these disadvantages embodied inthese well known diurectics produces compounds with insufficient potencyand/or effective half-life on mucosal surfaces to have therapeuticbenefit for hydrating mucosal surfaces.

Clearly, what is needed are drugs that are more effective at restoringthe clearance of mucus from the lungs of patients with CB/CF. The valueof these new therapies will be reflected in improvements in the qualityand duration of life for both the CF and the CB populations.

Other mucosal surfaces in and one the body exhibit subtle differences inthe normal physiology of the protective surface liquids on theirsurfaces but the pathophysiology of disease reflects a common theme,i.e., too little protective surface liquid. For example, in xerostomia(dry mouth) the oral cavity is depleted of liquid due to a failure ofthe parotid sublingual and submandibular glands to secrete liquiddespite continued Na⁺ (ENaC) transport mediated liquid absorption fromthe oral cavity. Similarly, keratoconjunctivitis sira (dry eye) iscaused by failure of lacrimal glands to secrete liquid in the face ofcontinued Na⁺ dependent liquid absorption on conjunctional surfaces. Inrhinosinusitis, there is an imbalance, as in CB, between mucin secretionand relative ASL depletion. Finally, in the gastrointestinal tract,failure to secrete C1⁻ (and liquid) in the proximal small intestine,combined with increased Na⁺ (and liquid) absorption in the terminalileum leads to the distal intestinal obstruction syndrome (DIOS). Inolder patients excessive Na⁺ (and volume) absorption in the descendingcolon produces constipation and diverticulitis.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide compounds that aremore potent and/or absorbed less rapidly from mucosal surfaces, and/orare less reversible as compared to known compounds.

It is another aspect of the present invention to provide compounds offormula (I) that are more potent and/or absorbed less rapidly and/orexhibit less reversibility, as compared to compounds such as amilorde,benzamil, and phenamil. Therefore, the compounds of formula (I) willgive a prolonged pharmacodynamic half-life on mucosal surfaces ascompared to known compounds.

It is another object of the present invention to provide compounds offormula (I) which are (1) absorbed less rapidly from mucosal surfaces,especially airway surfaces, as compared to known compounds and; (2) whenabsorbed from mucosal surfaces after administration to the mucosalsurfaces, are converted in vivo into metabolic derivatives thereof whichhave reduced efficacy in blocking sodium channels as compared to theadministered parent compound.

It is another object of the present invention to provide compounds offormula (I) that are more potent and/or absorbed less rapidly and/orexhibit less reversibility, as compared to compounds such as amiloride,benzamil, and phenamil. Therefore, the compounds of formula (I) willgive a prolonged pharmacodynamic half-life on mucosal surfaces ascompared to previous compounds.

It is another object of the present invention to provide methods oftreatment which take advantage of the properties described above.

The objects of the present invention may be accomplished with a class ofpyrazinoylguanidine compounds represented by a compound represented byformula (I):

wherein

X is hydrogen, halogen, trifluoromethyl, lower alkyl, unsubstituted orsubstituted phenyl, lower alkyl-thio, phenyl-lower alkyl-thio, loweralkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl;

Y is hydrogen, hydroxyl, mercapto, lower alkoxy, lower alkyl-thio,halogen, lower alkyl, unsubstituted or substituted mononuclear aryl, or—N(R²)₂;

R¹ is hydrogen or lower alkyl;

each R² is, independently, —R⁷, —(CH₂)_(m)—OR⁸, —(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)—Z_(g)—R⁷, —(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

R³ and R⁴ are each, independently, hydrogen, a group represented byformula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), loweralkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-lower alkyl,with the proviso that at least one of R³ and R⁴ is a group representedby formula (A):

wherein

each R^(L) is, independently, —R⁷, —(CH₂)_(n)—OR⁸, —O—(CH₂)_(m)—OR⁸,—(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)—(Z)_(g)—R⁷,—O—(CH₂)_(m)—(Z)_(g)—R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose, or

each x is, independently, O, NR⁷, C═O, CHOH, C═N—R⁶, or represents asingle bond;

each o is, independently, an integer from 0 to 10;

each p is, independently, an integer from 0 to 10;

with the proviso that (a) the sum of o and p in each contiguous chain isfrom 1 to 10 when x is O, NR⁷, C═O, or C═N—R⁶ or (b) that the sum of oand p in each contiguous chain is from 4 to 10 when x represents asingle bond;

each R⁶ is, independently, —R⁷, —OH, —OR¹¹, —N(R⁷)₂, —(CH₂)_(m)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)—(Z)_(g)—R⁷,—O—(CH₂)_(m)—(Z)_(g)—R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, O-glucuronide, O-glucose,

wherein when two R⁶ are —OR¹¹ and are located adjacent to each other ona phenyl ring, the alkyl moieties of the two R⁶ may be bonded togetherto form a methylenedioxy group;

-   -   each R⁷ is, independently, hydrogen or lower alkyl;    -   each R⁸ is, independently, hydrogen, lower alkyl, —C(═O)—R¹¹,        glucuronide, 2-tetrahydropyranyl, or

-   -   each R⁹ is, independently, —CO₂R⁷, —CON(R⁷)₂, —SO₂CH₃, or        —C(═O)R⁷;    -   each R¹⁰ is, independently, —H, —SO₂CH₃, —CO₂R⁷, —C(═O)NR⁷R⁹,        —C(═O)R⁷, or —CH₂—(CHOH)_(n)—CH₂OH;    -   each Z is, independently, CHOH, C(═O), CHNR⁷R¹⁰, C═NR¹⁰, or        NR¹⁰;    -   each R¹¹ is, independently, lower alkyl;    -   each g is, independently, an integer from 1 to 6;    -   each m is, independently, an integer from 1 to 7;    -   each n is, independently, an integer from 0 to 7;    -   each Q is, independently, C—R⁶ or a nitrogen atom, wherein at        most 3 Q in a ring are nitrogen atoms;    -   or a pharmaceutically acceptable salt thereof, and    -   inclusive of all enantiomers, diastereomers, and racemic        mixtures thereof.

The present also provides pharmaceutical compositions which contain acompound represented above.

The present invention also provides a method of promoting hydration ofmucosal surfaces, comprising:

administering an effective amount of a compound represented by formula(I) to a mucosal surface of a subject.

The present invention also provides a method of restoring mucosaldefense, comprising:

topically administering an effective amount of compound represented byformula (I) to a mucosal surface of a subject in need thereof.

The present invention also provides a method of blocking ENaC,comprising:

contacting sodium channels with an effective amount of a compoundrepresented by formula (I).

The present invention also provides a method of promoting mucusclearance in mucosal surfaces, comprising:

administering an effective amount of a compound represented by formula(I) to a mucosal surface of a subject.

The present invention also provides a method of treating chronicbronchitis, comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating cysticfibrosis, comprising:

administering an effective amount of compound represented by formula (I)to a subject in need thereof.

The present invention also provides a method of treating rhinosinusitis,comprising:

administering an effective amount of a compound represented by a formula(I) to a subject in need thereof.

The present invention also provides a method of treating nasaldehydration, comprising:

administering an effective amount of a compound represented by formula(I) to the nasal passages of a subject in need thereof.

The present invention also provides a method of treating nasaldehydration, where the nasal dehydration is brought on by administeringdry oxygen to the subject.

The present invention also provides a method of treating sinusitis,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating pneumonia,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of preventingventilator-induced pneumonia, comprising:

administering an effective compound represented by formula (I) to asubject by means of a ventilator.

The present invention also provides a method of treating asthma,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating primary ciliarydyskinesia, comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating otitis media,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of inducing sputum fordiagnostic purposes, comprising:

administering an effective amount of compound represented by formula (I)to a subject in need thereof.

The present invention also provides a method of treating chronicobstructive pulmonary disease, comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating emphysema,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating dry eye,comprising:

administering an effective amount of a compound represented by formula(I) to the eye of the subject in need thereof.

The present invention also provides a method of promoting ocularhydration, comprising:

administering an effective amount of a compound represented by formula(I) to the eye of the subject.

The present invention also provides a method of promoting cornealhydration, comprising:

administering an effective amount of a compound represented by formula(I) to the eye of the subject.

The present invention also provides a method of treating Sjögren'sdisease, comprising:

administering an effective amount of compound represented by formula (I)to a subject in need thereof.

The present invention also provides a method of treating vaginaldryness, comprising:

administering an effective amount of a compound represented by formula(I) to the vaginal tract of a subject in need thereof.

The present invention also provides a method of treating dry skin,comprising:

administering an effective amount of a compound represented by formula(I) to the skin of a subject in need thereof.

The present invention also provides a method of treating dry mouth(xerostomia), comprising:

administering an effective amount of compound represented by formula (I)to the mouth of the subject in need thereof.

The present invention also provides a method of treating distalintestinal obstruction syndrome, comprising:

administering an effective amount of compound represented by formula (I)to a subject in need thereof.

The present invention also provides a method of treating esophagitis,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

The present invention also provides a method of treating constipation,comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof. In one embodiment of this method, thecompound is administered either orally or via a suppository or enema.

The present invention also provides a method of treating chronicdiverticulitis comprising:

administering an effective amount of a compound represented by formula(I) to a subject in need thereof.

BRIEF DESCRIPTION OF THE FIGURES

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description consideredin conjunction with the following figures:

FIG. 1: Effect of a compound of the present invention on MCC at t=0 hrsas described in Example 9 herein.

FIG. 2: Effect of a compound of the present invention on MCC at t=4 hrsas described in Example 9 herein.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is based on the discovery that the compounds offormula (I) are more potent and/or, absorbed less rapidly from mucosalsurfaces, especially airway surfaces, and/or less reversable frominteractions with ENaC as compared to compounds such as amiloride,benzamil, and phenamil. Therefore, the compounds of formula have ahigher half-life on mucosal surfaces as compared to these compounds.

The present invention is also based on the discover that certaincompounds embraced by formula (I) are converted in vivo into metabolicderivatives thereof which have reduced efficacy in blocking sodiumchannels as compared to the parent administered compound, after they areabsorbed form mucosal surfaces after administration. This importantproperty means that the compounds will have a lower tendency to causeundesired side-effects by blocking sodium channels located at untargetedlocations in the body of the recipient, e.g., in the kidneys.

In the compounds represented by formula (I), X may be hydrogen, halogen,trifluoromethyl, lower alkyl, lower cycloalkyl, unsubstituted orsubstituted phenyl, lower alkyl-thio, phenyl-lower alkyl-thio, loweralkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl. Halogen is preferred.

Examples of halogen include fluorine, chlorine, bromine, and iodine.Chlorine and bromine are the preferred halogens. Chlorine isparticularly preferred. This description is applicable to the term“halogen” as used throughout the present disclosure.

As used herein, the term “lower alkyl” means an alkyl group having lessthan 8 carbon atoms. This range includes all specific values of carbonatoms and subranges therebetween, such as 1 ,2, 3, 4, 5, 6, and 7 carbonatoms. The term “alkyl” embraces all types of such groups, e.g., linear,branched, and cyclic alkyl groups. This description is applicable to theterm “lower alkyl” as used throughout the present disclosure. Example ofsuitable lower alkyl groups include methyl, ethyl, propyl, cyclopropyl,butyl, isobutyl, etc.

Substituents for the phenyl group include halogens. Particularlypreferred halogen substituents are chlorine and bromine.

Y may be hydrogen, hydroxyl, mercapto, lower alkoxy, lower alkyl-thio,halogen, lower alkyl, lower cycloalkyl, mononuclear aryl, or —N(R²)₂.The alkyl moiety of the lower alkoxy groups is the same as describedabove. Examples of mononuclear aryl include phenyl groups. The phenylgroup may be unsubstituted or substituted as described above. Thepreferred identity of Y is —N(R²)₂. Particularly preferred are suchcompounds where each R² is hydrogen.

R¹ may be hydrogen or lower alkyl. Hydrogen is preferred for R¹.

Each R² may be, independently, —R⁷, —(CH₂)_(m)—OR⁸, —(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)—Z_(g)—R⁷,—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

Hydrogen and lower alkyl, particularly C₁–C₃ alkyl are preferred for R².Hydrogen is particularly preferred.

R³ and R⁴ may be, independently, hydrogen, a group represented byformula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), lower(alkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-loweralkyl, provided that at least one of R³ and R⁴ is a group represented byformula (A).

Preferred compounds are those where one of R³ and R⁴ is hydrogen and theother is represented by formula (A).

In formula (A), the moiety —(C(R^(L))₂)_(o)-x-(C(R^(L))₂)_(p)— definesan alkylene group bonded to the aromatic ring. The variables o and p mayeach be an integer from 0 to 10, subject to the proviso that the sum ofo and p in the chain is from 1 to 10. Thus, o and p may each be 0, 1, 2,3, 4, 5, 6, 7, 8, 9, or 10. Preferably, the sum of o and p is from 2 to6. In a particularly preferred embodiment, the sum of o and p is 4.

The linking group in the alkylene chain, x, may be, independently, O,NR¹⁰, C(═O), CHOH, C(═N—R¹⁰), CHNR⁷R¹⁰, or represents a single bond;

Therefore, when x represents a single bond, the alkylene chain bonded tothe ring is represented by the formula —(C(R^(L))₂)_(o+p)—, in which thesum o+p is from 1 to 10.

Each R^(L) may be, independently, —R⁷, —(CH₂)_(n)—OR⁸, —O—(CH₂)_(m)—OR⁸,—(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)—(Z)_(g)—R⁷,—O—(CH₂)_(m)—(Z)_(g)—R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, O-glucuronide, O-glucose, or

The preferred R^(L) groups include —H, —OH, —N(R⁷)₂, especially whereeach R⁷ is hydrogen.

In the alkylene chain in formula (A), it is preferred that when oneR^(L) group bonded to a carbon atoms is other than hydrogen, then theother R^(L) bonded to that carbon atom is hydrogen, i.e., the formula—CHR^(L)—. It is also preferred that at most two R^(L) groups in analkylene chain are other than hydrogen, where in the other R^(L) groupsin the chain are hydrogens. Even more preferably, only one R^(L) groupin an alkylene chain is other than hydrogen, where in the other R^(L)groups in the chain are hydrogens. In these embodiments, it ispreferable that x represents a single bond.

In another particular embodiment of the invention, all of the R^(L)groups in the alkylene chain are hydrogen. In these embodiments, thealkylene chain is represented by the formula —(CH₂)_(o)-x-(CH₂)_(p)—.

There are four R⁶ groups present on the ring in formula (A). Each R⁶ maybe each, independently, —R⁷, —OH, —OR¹¹, —N(R⁷)₂, —(CH₂)_(m)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)-(Z)_(g)-R⁷,—O—(CH₂)_(m)-(Z)_(g)-R⁷,—(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, O-glucuronide, O-glucose,

When two R⁶ are —OR¹¹ and are located adjacent to each other on a phenylring, the alkyl moieties of the two R⁶ groups may be bonded together toform a methylenedioxy group, i.e., a group of the formula —O—CH₂—O—.

As discussed above, R⁶ may be hydrogen. Therefore, 1, 2, 3, or 4 R⁶groups may be other than hydrogen. Preferably at most 3 of the R⁶ groupsare other than hydrogen.

Each g is, independently, an integer from 1 to 6. Therefore, each g maybe 1, 2, 3, 4, 5, or 6.

Each m is an integer from 1 to 7. Therefore, each m may be 1, 2, 3, 4,5, 6, or 7.

Each n is an integer from 0 to 7. Therefore, each n maybe 0, 1, 2, 3, 4,5, 6, or 7.

Each Q in formula (A) is C—R⁶ or a nitrogen atom, where at most three Qin a ring are nitrogen atoms. Thus, there may be 1, 2, or 3 nitrogenatoms in a ring. Preferably, at most two Q are nitrogen atoms. Morepreferably, at most one Q is a nitrogen atom. In one particularembodiment, the nitrogen atom is at the 3-position of the ring. Inanother embodiment of the invention, each Q is C—R⁶, i.e., there are nonitrogen atoms in the ring.

In a preferred embodiment of the present invention:

X is halogen;

Y is —N(R⁷)₂;

R¹ is hydrogen or C₁–C₃ alkyl; —(CH₂)_(n)—CO₂R⁷;

R² is —R⁷, —(CH₂)_(m)—OR⁷, or —CO₂R⁷;

R³ is a group represented by formula (A); and

R⁴ is hydrogen, a group represented by formula (A), or lower alkyl;

In another preferred embodiment of the present invention:

X is chloro or bromo;

Y is —N(R⁷)₂;

R² is hydrogen or C₁–C₃ alkyl;

at most three R⁶ are other than hydrogen as described above;

at most three R^(L) are other than hydrogen as described above; and

at most 2 Q are nitrogen atoms.

In another preferred embodiment of the present invention:

Y is —NH₂.

In another preferred embodiment of the present invention:

R⁴ is hydrogen;

at most one R^(L) is other than hydrogen as described above;

at most two R⁶ are other than hydrogen as described above; and

at most 1 Q is a nitrogen atom.

In another preferred embodiment of the present invention, x is O, NR⁷,C═O, CHOH, or C═N—R⁶. In another preferred embodiment of the presentinvention, x represents a single bond.

In another preferred embodiment of the present invention, each R⁶ ishydrogen. In another preferred embodiment of the present invention, atmost two R⁶ are other than hydrogen as described above. In anotherpreferred embodiment of the present invention, one R⁶ is other thanhydrogen as described above. In another preferred embodiment of thepresent invention, one R⁶ is —OH.

In another preferred embodiment of the present invention, each R^(L) ishydrogen. In another preferred embodiment of the present invention, atmost two R^(L) are other than hydrogen as described above. In anotherpreferred embodiment of the present invention, one R^(L) is other thanhydrogen as described above.

In another preferred embodiment of the present invention, x represents asingle bond and the sum of o and p is 4 to 6.

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

In another preferred embodiment of the present invention the compound offormula (I) is represented by the formula:

The compounds of formula (I) may be prepared and used as the free base.Alternatively, the compounds may be prepared and used as apharmaceutically acceptable salt. Pharmaceutically acceptable salts aresalts that retain or enhance the desired biological activity of theparent compound and do not impart undesired toxicological effects.Examples of such salts are (a) acid addition salts formed with inorganicacids, for example, hydrochloric acid, hydrobromic acid, sulfuric acid,phosphoric acid, nitric acid and the like; (b) salts formed with organicacids such as, for example, acetic acid, oxalic acid, tartaric acid,succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid,malic acid, ascorbic acid, benzoic acid, tannic acid, palmitic acid,alginic acid, polyglutamic acid, naphthalenesulfonic acid,methanesulfonic acid, p-toluenesulfonic acid, naphthalenedisulfonicacid, polygalacturonic acid, malonic acid, sulfosalicylic acid, glycolicacid, 2-hydroxy-3-naphthoate, pamoate, salicylic acid, stearic acid,phthalic acid, mandelic acid, lactic acid and the like; and (c) saltsformed from elemental anions for example, chlorine, bromine, and iodine.

It is to be noted that all enantiomers, diastereomers, and racemicmixtures of compounds within the scope of formula (I) are embraced bythe present invention. All mixtures of such enantiomers anddiastereomers are within the scope of the present invention.

Without being limited to any particular theory, it is believed that thecompounds of formula (I) function in vivo as sodium channel blockers. Byblocking epithelial sodium channels present in mucosal surfaces thecompounds of formula (I) reduce the absorption of water by the mucosalsurfaces. This effect increases the volume of protective liquids onmucosal surfaces, rebalances the system, and thus treats disease.

The present invention also provides methods of treatment that takeadvantage of the properties of the compounds of formula (I) discussedabove. Thus, subjects that may be treated by the methods of the presentinvention include, but are not limited to, patients afflicted withcystic fibrosis, primary ciliary dyskinesia, chronic bronchitis, chronicobstructive airway disease, artificially ventilated patients, patientswith acute pneumonia, etc. The present invention may be used to obtain asputum sample from a patient by administering the active compounds to atleast one lung of a patient, and then inducing or collecting a sputumsample from that patient. Typically, the invention will be administeredto respiratory mucosal surfaces via aerosol (liquid or dry powders) orlavage.

Subjects that may be treated by the method of the present invention alsoinclude patients being administered supplemental oxygen nasally (aregimen that tends to dry the airway surfaces); patients afflicted withan allergic disease or response (e.g., an allergic response to pollen,dust, animal hair or particles, insects or insect particles, etc.) thataffects nasal airway surfaces; patients afflicted with a bacterialinfection e.g., staphylococcus infections such as Staphylococcus aureusinfections, Hemophilus influenza infections, Streptococcus pneumoniaeinfections, Pseudomonas aeuriginosa infections, etc.) of the nasalairway surfaces; patients afflicted with an inflammatory disease thataffects nasal airway surfaces; or patients afflicted with sinusitis(wherein the active agent or agents are administered to promote drainageof congested mucous secretions in the sinuses by administering an amounteffective to promote drainage of congested fluid in the sinuses), orcombined, Rhinosinusitis. The invention may be administered torhino-sinal surfaces by topical delivery, including aerosols and drops.

The present invention may be used to hydrate mucosal surfaces other thanairway surfaces. Such other mucosal surfaces include gastrointestinalsurfaces, oral surfaces, genito-urethral surfaces, ocular surfaces orsurfaces of the eye, the inner ear and the middle ear. For example, theactive compounds of the present invention may be administered by anysuitable means, including locally/topically, orally, or rectally, in aneffective amount.

The present invention is concerned primarily with the treatment of humansubjects, but may also be employed for the treatment of other mammaliansubjects, such as dogs and cats, for veterinary purposes.

As discussed above, the compounds used to prepare the compositions ofthe present invention may be in the form of a pharmaceuticallyacceptable free base. Because the free base of the compound is generallyless soluble in aqueous solutions than the salt, free base compositionsare employed to provide more sustained release of active agent to thelungs. An active agent present in the lungs in particulate form whichhas not dissolved into solution is not available to induce aphysiological response, but serves as a depot of bioavailable drug whichgradually dissolves into solution.

Another aspect of the present invention is a pharmaceutical composition,comprising a compound of formula (I) in a pharmaceutically acceptablecarrier (e.g., an aqueous carrier solution). In general, the compound offormula (I) is included in the composition in an amount effective toinhibit the reabsorption of water by mucosal surfaces.

The compounds of the present invention may also be used in conjunctionwith a P2Y2 receptor agonist or a pharmaceutically acceptable saltthereof (also sometimes referred to as an “active agent” herein). Thecomposition may further comprise a P2Y2 receptor agonist or apharmaceutically acceptable salt thereof (also sometimes referred to asan “active agent” herein). The P2Y2 receptor agonist is typicallyincluded in an amount effective to stimulate chloride and watersecretion by airway surfaces, particularly nasal airway surfaces.Suitable P2Y2 receptor agonists are described in columns 9–10 of U.S.Pat. Nos. 6,264,975, 5,656,256, and 5,292,498, each of which isincorporated herein by reference.

Bronchodiloators can also be used in combination with compounds of thepresent invention. These Bronchodilators include, but are not limitedto, β-adrenergic agonists including but not limited to epinephrine,isoproterenol, fenoterol, albutereol, terbutalin, pirbuterol,bitolterol, metaproterenol, iosetharine, salmeterol xinafoate, as wellas anticholinergic agents including but not limited to ipratropiumbromide, as well as compounds such as theophylline and aminophylline.These compounds may be administered in accordance with known techniques,either prior to or concurrently with the active compounds describedherein.

Another aspect of the present invention is a pharmaceutical formulation,comprising an active compound as described above in a pharmaceuticallyacceptable carrier (e.g., an aqueous carrier solution). In general, theactive compound is included in the composition in an amount effective totreat mucosal surfaces, such as inhibiting the reabsorption of water bymucosal surfaces, including airway and other surfaces.

The active compounds disclosed herein may be administered to mucosalsurfaces by any suitable means, including topically, orally, rectally,vaginally, ocularly and dermally, etc. For example, for the treatment ofconstipation, the active compounds may be administered orally orrectally to the gastrointestinal mucosal surface. The active compoundmay be combined with a pharmaceutically acceptable carrier in anysuitable form, such as sterile physiological or dilute saline or topicalsolution, as a droplet, tablet or the like for oral administration, as asuppository for rectal or genito-urethral administration, etc.Excipients may be included in the formulation to enhance the solubilityof the active compounds, as desired.

The active compounds disclosed herein may be administered to the airwaysurfaces of a patient by any suitable means, including as a spray, mist,or droplets of the active compounds in a pharmaceutically acceptablecarrier such as physiological or dilute saline solutions or distilledwater. For example, the active compounds may be prepared as formulationsand administered as described in U.S. Pat. No. 5,789,391 to Jacobus, thedisclosure of which is incorporated by reference herein in its entirety.

Solid or liquid particulate active agents prepared for practicing thepresent invention could, as noted above, include particles of respirableor non-respirable size; that is, for respirable particles, particles ofa size sufficiently small to pass through the mouth and larynx uponinhalation and into the bronchi and alveoli of the lungs, and fornon-respirable particles, particles sufficiently large to be retained inthe nasal airway passages rather than pass through the larynx and intothe bronchi and alveoli of the lungs. In general, particles ranging fromabout 1 to 5 microns in size (more particularly, less than about 4.7microns in size) are respirable. Particles of non-respirable size aregreater than about 5 microns in size, up to the size of visibledroplets. Thus, for nasal administration, a particle size in the rangeof 10–500 μm may be used to ensure retention in the nasal cavity.

In the manufacture of a formulation according to the invention, activeagents or the physiologically acceptable salts or free bases thereof aretypically admixed with, inter alia, an acceptable carrier. Of course,the carrier must be compatible with any other ingredients in theformulation and must not be deleterious to the patient. The carrier mustbe solid or liquid, or both, and is preferably formulated with thecompound as a unit-dose formulation, for example, a capsule, that maycontain 0.5% to 99% by weight of the active compound. One or more activecompounds may be incorporated in the formulations of the invention,which formulations may be prepared by any of the well-known techniquesof pharmacy consisting essentially of admixing the components.

Compositions containing respirable or non-respirable dry particles ofmicronized active agent may be prepared by grinding the dry active agentwith a mortar and pestle, and then passing the micronized compositionthrough a 400 mesh screen to break up or separate out largeagglomerates.

The particulate active agent composition may optionally contain adispersant which serves to facilitate the formulation of an aerosol. Asuitable dispersant is lactose, which may be blended with the activeagent in any suitable ratio (e.g., a 1 to 1 ratio by weight).

Active compounds disclosed herein may be administered to airway surfacesincluding the nasal passages, sinuses and lungs of a subject by ansuitable means know in the art, such as by nose drops, mists., etc. Inone embodiment of the invention, the active compounds of the presentinvention and administered by transbronchoscopic lavage. In a preferredembodiment of the invention, the active compounds of the presentinvention are deposited on lung airway surfaces by administering anaerosol suspension of respirable particles comprised of the activecompound, which the subject inhales. The respirable particles may beliquid or solid. Numerous inhalers for administering aerosol particlesto the lungs of a subject are known.

Inhalers such as those developed by Inhale Therapeutic Systems, PaloAlto, Calif., USA, may be employed, including but not limited to thosedisclosed in U.S. Pat. Nos. 5,740,794; 5,654,007; 5,458,135; 5,775,320;and 5,785,049. The Applicant specifically intends that the disclosuresof all patent references cited herein be incorporated by referenceherein in their entirety. Inhalers such as those developed by DuraPharmaceuticals, Inc., San Diego, Calif., USA, may also be employed,including but not limited to those disclosed in U.S. Pat. Nos.5,622,166; 5,577,497; 5,645,051; and 5,492,112. Additionally, inhalerssuch as those developed by Aradigm Corp., Hayward, Calif., USA, may beemployed, including but not limited to those disclosed in U.S. Pat. Nos.5,826,570; 5,813,397; 5,819,726; and 5,655,516. These apparatuses areparticularly suitable as dry particle inhalers.

Aerosols of liquid particles comprising the active compound may beproduced by any suitable means, such as with a pressure-driven aerosolnebulizer or an ultrasonic nebulizer. See, e.g., U.S. Pat. No.4,501,729. Nebulizers are commercially available devices which transformsolutions or suspensions of the active ingredient into a therapeuticaerosol mist either by means of acceleration of compressed gas,typically air or oxygen, through a narrow venturi orifice or by means ofultrasonic agitation. Suitable formulations for use in nebulizersconsist of the active ingredient in a liquid carrier, the activeingredient comprising up to 40% w/w of the formulation, but preferablyless than 20% w/w. The carrier is typically water (and most preferablysterile, pyrogen-free water) or dilute aqueous alcoholic solution.Perfluorocarbon carriers may also be used. Optional additives includepreservatives if the formulation is not made sterile, for example,methyl hydroxybenzoate, antioxidants, flavoring agents, volatile oils,buffering agents and surfactants.

Aerosols of solid particles comprising the active compound may likewisebe produced with any solid particulate medicament aerosol generator.Aerosol generators for administering solid particulate medicaments to asubject produce particles which are respirable, as explained above, andgenerate a volume of aerosol containing predetermined metered dose ofmedicament at a rate suitable for human administration. One illustrativetype of solid particulate aerosol generator is an insufflator. Suitableformulations for administration by insufflation include finelycomminuted powders which may be delivered by means of an insufflator ortaken into the nasal cavity in the manner of a snuff. In theinsufflator, the powder (e.g., a metered dose thereof effective to carryout the treatments described herein) is contained in capsules orcartridges, typically made of gelatin or plastic, which are eitherpierced or opened in situ and the powder delivered by air drawn throughthe device upon inhalation or by means of a manually-operated pump. Thepowder employed in the insufflator consists either solely of the activeingredient or of powder blend comprising the active ingredient, asuitable powder diluent, such as lactose, and an optional surfactant.The active ingredient typically comprises of 0.1 to 100% w/w of theformulation. A second type of illustrative aerosol generator comprises ametered dose inhaler. Metered dose inhalers are pressurized aerosoldispensers, typically containing a suspension or solution formulation ofactive ingredient in a liquified propellant. During use, these devicesdischarge the formulation through a valve adapted to deliver a meteredvolume, typically from 10 to 150 μl, to produce a fine particle spraycontaining the active ingredient. Suitable propellants include certainchlorofluorocarbon compounds, for example, dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane and mixtures thereof.The formulation may additionally contain one of more co-solvents, forexample, ethanol, surfactants, such as oleic acid or sorbitan trioleate,antioxidants and suitable flavoring agents.

The aerosol, whether formed from solid or liquid particles, may beproduced by the aerosol generator at a rate of from about 10 to 150liters per minute, more preferable from 30 to 150 liters per minute, andmost preferably about 60 liters per minute. Aerosols containing greateramounts of medicament may be administered more rapidly.

The dosage of the active compounds disclosed herein will vary dependingon the condition being treated and the state of the subject, butgenerally may be from about 0.01, 0.03, 0.05, 0.1, 1, 5 to about 10 or20 mg of the pharmaceutic agent, deposited on the airway surfaces. Thedaily dose may be divided among one or multiple unit doseadministrations. The goal is to achieve a concentration of thepharmaceutic agents on lung airway surfaces of between 10⁻⁹–10⁴ M.

In another embodiment, they are administered by administering an aerosolsuspension of respirable or non-respirable particles (preferablynon-respirable particles) comprised of active compound, which thesubject inhales through the nose. The respirable or non-respirableparticles may be liquid or solid. The quantity of active agent includedmay be an amount of sufficient to achieve dissolved concentrations ofactive agent on the airway surfaces of the subject of from about 10⁻⁹,10⁻⁸, or 10⁻⁷ to about 10⁻³, 10⁻², 10⁻¹ Moles and more preferably fromabout 10⁻⁹ to about 10⁻⁴ Moles/liter.

The dosage of active compound will vary depending on the condition beingtreated and the state of the subject, but generally may be an amountsufficient to achieve dissolved concentrations of active compound on thenasal airway surfaces of the subject from about 10⁻⁹, 10⁻⁸, 10⁻⁷ toabout 10⁻³, 10⁻², or 10⁻¹ Moles/liter, and more preferably from about10⁻⁷ to about 10⁻⁴ Moles/liter. Depending upon the solubility of theparticular formulation of active compound administered, the daily dosemay be divided among one or several unit dose administrations. The dailydose by weight may range from about 0.01, 0.03, 0.1, 0.5 or 1.0 to 10 or20 milligrams of active agent particles for a human subject, dependingupon the age and condition of the subject. A currently preferred unitdose is about 0.5 milligrams of active agent given at a regimen of 2–10administrations per day. The dosage may be provided as a prepackagedunit by any suitable means (e.g., encapsulating a gelatin capsule).

In one embodiment of the invention, the particulate active agentcomposition may contain both a free base of active agent and apharmaceutically acceptable salt to provide both early release andsustained release of active agent for dissolution into the mucussecretions of the nose. Such a composition serves to provide both earlyrelief to the patient, and sustained relief over time. Sustained relief,by decreasing the number of daily administrations required, is expectedto increase patient compliance with course of active agent treatments.

Pharmaceutical formulations suitable for airway administration includeformulations of solutions, emulsions, suspensions and extracts. Seegenerally, J. Nairn, Solutions, Emulsions, Suspensions and Extracts, inRemington: The Science and Practice of pharmacy, chap. 86 (19^(th) ed1995). Pharmaceutical formulations suitable for nasal administration maybe prepared as described in U.S. Pat. Nos. 4,389,393 to Schor; 5,707,644to Illum; 4,294,829 to Suzuki; and 4,835,142 to Suzuki; the disclosuresof which are incorporated by reference herein in the entirety.

Mists or aerosols of liquid particles comprising the active compound maybe produced by any suitable means, such as by a simple nasal spray withthe active agent in an aqueous pharmaceutically acceptable carrier, suchas a sterile saline solution or sterile water. Administration may bewith a pressure-driven aerosol nebulizer or an ultrasonic nebulizer. Seee.g. U.S. Pat. Nos. 4,501,729 and 5,656,256. Suitable formulations foruse in a nasal droplet or spray bottle or in nebulizers consist of theactive ingredient in a liquid carrier, the active ingredient comprisingup to 40% w/w of the formulation, but preferably less than 20% w/w.Typically the carrier is water (and most preferably sterile,pyrogen-free water) or dilute aqueous alcoholic solution, preferablymade in a 0.12% to 0.8% solution of sodium chloride. Optional additivesinclude preservatives if the formulation is not made sterile, forexample, methyl hydroxybenzoate, antioxidants, flavoring agents,volatile oils, buffering agents, osmotically active agents (e.g.mannitol, xylitol, erythritol) and surfactants.

Compositions containing respirable or non-respirable dry particles ofmicronized active agent may be prepared by grinding the dry active agentwith a mortar and pestle, and then passing the micronized compositionthrough a 400 mesh screen to break up or separate out largeagglomerates.

The particulate composition may optionally contain a dispersant whichserves to facilitate the formation of an aerosol. A suitable dispersantis lactose, which may be blended with the active agent in any suitableratio (e.g., a 1 to 1 ratio by weight).

The compounds of formula (I) may be synthesized according to proceduresknown in the art. A representative synthetic procedure is shown in thescheme below.

These procedures are described in, for example, E. J. Cragoe, “TheSynthesis of Amiloride and Its Analogs” (Chapter 3) in Amiloride and ItsAnalogs, pp. 25–36, incorporated herein by reference. Other methods ofpreparing the compounds are described in, for example, U.S. Pat. No.3,313,813, incorporated herein by reference. See in particular MethodsA, B, C, and D described in U.S. Pat. No. 3,313,813.

Several assays may be used to characterize the compounds of the presentinvention. Representative assays are discussed below.

In Vitro Measure of Sodium Channel Blocking Activity and Reversibility

One assay used to assess mechanism of action and/or potency of thecompounds of the present invention involves the determination of lumenaldrug inhibition of airway epithelial sodium currents measured undershort circuit current (I_(SC)) using airway epithelial monolayersmounted in Ussing chambers. Cells obtained from freshly excised human,dog, sheep or rodent airways are seeded onto porous 0.4 micron Snapwell™Inserts (CoStar), cultured at air-liquid interface (ALI) conditions inhormonally defined media, and assayed for sodium transport activity(I_(SC)) while bathed in Krebs Bicarbonate Ringer (KBR) in Usingchambers. All test drug additions are to the lumenal bath with half-logdose addition protocols (from 1×10⁻¹¹ M to 3×10⁻⁵M), and the cumulativechange in I_(SC) (inhibition) recorded. All drugs are prepared indimethyl sulfoxide as stock solutions at a concentration of 1×10⁻² M andstored at −20° C. Eight preparations are typically run in parallel; twopreparations per run incorporate amiloride and/or benzamil as positivecontrols. After the maximal concentration (5×10⁻⁵ M) is administered,the lumenal bath is exchanged three times with fresh drug-free KBRsolution, and the resultant I_(SC) measured after each wash forapproximately 5 minutes in duration. Reversibility is defined as thepercent return to the baseline value for sodium current after the thirdwash. All data from the voltage clamps are collected via a computerinterface and analyzed off-line.

Dose-effect relationships for all compounds are considered and analyzedby the Prism 3.0 program. IC₅₀ values, maximal effective concentrations,and reversibility are calculated and compared to amiloride and benzamilas positive controls.

Pharmacological Assays of Absorption

(1) Apical Disappearance Assay

Bronchial cells (dog, human, sheep, or rodent cells) are seeded at adensity of 0.25×10⁶/cm² on a porous Transwell-Col collagen-coatedmembrane with a growth area of 1.13 cm² grown at an air-liquid interfacein hormonally defined media that promotes a polarized epithelium. From12 to 20 days after development of an air-liquid interface (ALI) thecultures are expected to be >90% ciliated, and mucins will accumulate onthe cells. To ensure the integrity of primary airway epithelial cellpreparations, the transepithelial resistance (R_(t)) and transepithelialpotential differences (PD), which are indicators of the integrity ofpolarized nature of the culture, are measured. Human cell systems arepreferred for studies of rates of absorption from apical surfaces. Thedisappearance assay is conducted under conditions that mimic the “thin”films in vivo (˜25 μl) and is initiated by adding experimental sodiumchannel blockers or positive controls (amiloride, benzamil, phenamil) tothe apical surface at an initial concentration of 10 μM. A series ofsamples (5 μl volume per sample) is collected at various time points,including 0, 5, 20, 40, 90 and 240 minutes. Concentrations aredetermined by measuring intrinsic fluorescence of each sodium channelblocker using a Fluorocount Microplate Flourometer or HPLC. Quantitativeanalysis employs a standard curve generated from authentic referencestandard materials of known concentration and purity. Data analysis ofthe rate of disappearance is performed using nonlinear regression, onephase exponential decay (Prism V 3.0).

2. Confocal Microscopy Assay of Amiloride Congener Uptake

Virtually all amiloride-like molecules fluoresce in the ultravioletrange. This property of these molecules may be used to directly measurecellular update using x-z confocal microscopy. Equimolar concentrationsof experimental compounds and positive controls including amiloride andcompounds that demonstrate rapid uptake into the cellular compartment(benzamil and phenamil) are placed on the apical surface of airwaycultures on the stage of the confocal microscope. Serial x-z images areobtained with time and the magnitude of fluorescence accumulating in thecellular compartment is quantitated and plotted as a change influorescence versus time.

3. In vitro Assays of Compound Metabolism

Airway epithelial cells have the capacity to metabolize drugs during theprocess of transepithelial absorption. Further, although less likely, itis possible that drugs can be metabolized on airway epithelial surfacesby specific ectoenzyme activities. Perhaps more likely as anecto-surface event, compounds may be metabolized by the infectedsecretions that occupy the airway lumens of patients with lung disease,e.g. cystic fibrosis. Thus, a series of assays is performed tocharacterize the compound metabolism that results from the interactionof test compounds with human airway epithelia and/or human airwayepithelial lumenal products.

In the first series of assays, the interaction of test compounds in KBRas an “ASL” stimulant are applied to the apical surface of human airwayepithelial cells grown in the T-Col insert system. For most compounds,we test for metabolism (generation of new species) using highperformance liquid chromatography (HPLC) to resolve chemical species andthe endogenous fluorescence properties of these compounds to estimatethe relative quantities of test compound and novel metabolites. For atypical assay, a test solution (25 μl KBR, containing 10 μM testcompound) is placed on the epithelial lumenal surface. Sequential 5 to10 μl samples are obtained from the lumenal and serosal compartments forHPLC analysis of (1) the mass of test compound permeating from thelumenal to serosal bath and (2) the potential formation of metabolitesfrom the parent compound. In instances where the fluorescence propertiesof the test molecule are not adequate for such characterizations,radiolabeled compounds are used for these assays. From the HPLC data,the rate of disappearance and/or formation of novel metabolite compoundson the lumenal surface and the appearance of test compound and/or novelmetabolite in the basolateral solution is quantitated. The data relatingthe chromatographic mobility of potential novel metabolites withreference to the parent compound are also quantitated.

To analyze the potential metabolism of test compounds by CF sputum, a“representative” mixture of expectorated CF sputum obtained from 10 CFpatients (under IRB approval) has been collected. The sputum has been besolubilized in a 1:5 mixture of KBR solution with vigorous vortexing,following which the mixture was split into a “neat” sputum aliquot andan aliquot subjected to ultracentrifugation so that a “supernatant”aliquot was obtained (neat=cellular; supernatant=liquid phase). Typicalstudies of compound metabolism by CF sputum involve the addition ofknown masses of test compound to “neat” CF sputum and aliquots of CFsputum “supernatant” incubated at 37° C., followed by sequentialsampling of aliquots from each sputum type for characterization ofcompound stability/metabolism by HPLC analysis as described above. Asabove, analysis of compound disappearance, rates of formation of novelmetabolites, and HPLC mobilities of novel metabolites are thenperformed.

4. Pharmacological Effects and Mechanism of Action of the Drug inAnimals

The effect of compounds for enhancing mucociliary clearance (MCC) can bemeasured using an in vivo model described by Sabater et al., Journal ofApplied Physiology, 1999, pp. 2191–2196, incorporated herein byreference.

EXAMPLES

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples which are providedherein for purposes of illustration only and are not intended to belimiting unless otherwise specified.

Materials and methods. All reagents and solvents were purchased fromAldrich Chemical Corp. and used without further purification. NMRspectra were obtained on either a Bruker WM 360 (¹H NMR at 360 MHZ and¹³C NMR at 90 MHZ) or a Bruker AC 300 (¹H NMR at 300 MHZ and ¹³C NMR at75 MHZ). Flash chromatography was performed on a Flash Elute™ systemfrom Elution Solution (PO Box 5147, Charlottesville, Va. 22905) chargedwith a 90 g silica gel cartridge (40M FSO-0110–040155, 32–63 μm) at 20psi (N₂). GC-analysis was performed on a Shimadzu GC-17 equipped with aHeliflex Capillary Column (Alltech); Phase: AT-1, Length: 10 meters, ID:0.53 mm, Film: 0.25 micrometers. GC Parameters: Injector at 320° C.,Detector at 320° C., FID gas flow: H₂ at 40 ml/min., Air at 400 ml/min.Carrier gas: Split Ratio 16:1, N₂ flow at 15 ml/min., N₂ velocity at 18cm/sec. The temperature program is 70° C. for 0–3 min, 70–300° C. from3–10 min, 300° C. from 10–15 min.

HPLC analysis was performed on a Gilson 322 Pump, detector UV/Vis-156 at360 mm, equipped with a Microsorb MV C8 column, 100 A, 25 cm. Mobilephase: A=acetonitrile with 0.1% TFA, B=water with 0.1% TFA. Gradientprogram: 95:5 B:A for 1 min, then to 20:80 B:A over 7 min, then to 100%A over 1 min, followed by washout with 100% A for 11 min, flow rate: 1ml/min.

Example 14-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V)

The title compound was prepared as shown in Scheme 1 below. The4-(4-hydroxyphenylbutyl)amine was prepared by routine organictransformations described in the following procedures. The coupling wasdone in accordance with the procedure described by Cragoe, E. J. Jr.,Oltersdorf, O. W. Jr. and delSolms. S. J. (1981) U.S. Pat. No.4,246,406, both incorporated herein by reference. The work up andpurification were modified in accordance with the physical properties ofV.

4-Methylphenylsulfonic acid 4-(4-methoxyphenyl)butyl ester (I).

Pyridine (15 mL) was added dropwise to a cooled (0° C.) solution of4-(4-methoxyphenyl)butanol (10.0 g, 0.055 mol) and p-toluenesulfonylchloride (13.6 g, 0.072 mol) in dry chloroform (100 mL) under stirring.The reaction mixture was stirred overnight at room temperature. Afterthis time, the reaction was quenched with 10% HCl (300 mL) and extractedwith chloroform. The organic fraction was washed with saturated NaHCO₃,water and dried over magnesium sulfate. The solvent was removed underreduced pressure and the residue purified by flash chromatography(eluent: hexane, ethyl acetate=15:1) to provide 12.9 g (66%) of I asclear oil. ¹H NMR (360 MHZ, CDCl₃) δ 1.61 (m, 4H), 2.44 (s, 3H), 2.52(m, 2H), 3.78 (s, 3H), 4.05 (m, 2H), 6.77 (d, J=12.5 Hz, 2H), 7.05 (d,J=12.5 Hz, 2H), 7.34 (d, J=10.5 Hz, 2H), 7.78 (d, J=10.5 Hz, 2H).

4-(4-Methoxyphenyl)butylazide (II).

Sodium azide (3.07 g, 0.047 mol) was added to a solution of II (12.9 g,0.04 mol) in anhydrous DMF (70 mL) and the reaction mixture was stirred12 h at 80° C. (oil bath). Then solvent was removed at reduced pressureand the residual oil was treated with a mixture of CH₂Cl₂:ether=3:1 (100mL). The resulting solution was washed with water (2×100 mL), brine anddried over magnesium sulfate. The solvent was removed under reducedpressure and 7.6 g (95%) of II was obtained. The purity of II (99%) wasdetermined by GC and TLC (eluent:hexane, ethyl acetate=1:1), R_(f)=0.84.

4-(4-Methoxyphenyl)butylamine (III).

Lithium aluminum hydride (55 mL of a 1M solution in THF, 0.055 mol) wasadded drop wise to a solution of II (7.6 g, 0.037 mol) in dry THF (70mL) at 0° C. and stirred overnight at room temperature in an argonatmosphere. The reaction mixture was treated with water (1.5 mL), then15% NaOH (1.5 mL), then with more water (3 mL) and filtered. The solidprecipitate was washed with THF. The combined organic fractions weredried over magnesium sulfate and the solvent was removed under reducedpressure to give 6.2 g (94%) of III. The purity of III (99%) wasdetermined by GC. ¹H NMR (360 MHz, DMSO-d₆) δ 1.34 (m, 2H), 1.54 (m,2H), 2.51 (m, 4H), 3.70 (s, 3H), 6.83 (d, J=8.6 Hz, 2H), 7.08 (d, J=8.3Hz, 2H); ¹³C(90 MHz, DMSO-d₆) δ 28.6, 330, 34.1, 41.5, 54.8, 113.1,129.1, 132.2, 157.3

4-(4-Hydroxyphenyl)butylamine hydrobromide (IV).

Amine III (2.32 g, 0.012 mol) was stirred in boiling 48% HBr (50 mL) for3 h. After the reaction was completed, argon was bubbled through thesolution and the solvent was evaporated under reduced pressure. Thesolid residue was dried above KOH to provide 3.1 g (90%) of IV. API MSm/z=166[C₁₀H₁₅NO+H]⁺

4-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V).

1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.4 g, 1.03 mmol) was added to a suspension of4-(4-hydroxyphenyl)butylamine hydrobromide (IV) in a mixture of THF (35mL) and triethylamine (3 mL). The reaction mixture was stirred at refluxtemperature for 3 h, then the supernatant was separated and the solventwas removed under reduced pressure. The oily residue was washed withwater (2×30 mL), ether (3×30 mL) and then 10% HCl (40 mL) was added. Themixture was vigorously stirred for 10 min then the yellow solid wasfiltered off, dried and recrystallized twice from ethanol to give 181 mg(41%) of V as yellow solid. Purity is 98% by HPLC, retention time is9.77 min; ¹H NMR (300 MHz, DMSO-d₆) δ 1.56 (br s, 4H), 2.48 (br s, 2H),3.35 (m, 2H), 6.65 (d, J=8.5 Hz, 2H), 6.95 (d, J=8.6 Hz, 2H), 7.50 (brs, 2H), 8.75 (br s, 1H), 9.05 (br .s, 1H), 9.33 (br s, 2H), 10.55 (s,1H); ¹³C NMR (75 MHz, CD₃OD) 28.7, 29.8, 35.4, 42.4, 111.2, 116.1,122.0, 130.0, 134.0, 155.0, 156.1, 156.8, 157.5, 167.0; APCI MS m/z=378[C₁₆H₂₀ClN₇O₂+H]⁺.

Example 24-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

4-Methylphenylsulfonic acid 4-(4-methoxyphenyl)butyl ester (1).

Pyridine (15 mL) was added drop wise to a cooled (0° C.) solution of4-(4-methoxyphenyl)butanol (10.0 g, 0.055 mol) and p-toluenesulfonylchloride (13.6 g, 0.072 mol) in dry chloroform (100 mL) under stirring.The reaction mixture was stirred overnight at room temperature. Afterthis time, the reaction was quenched with 10% HCl (300 mL) and extractedwith chloroform. The organic fraction was washed with saturated NaHCO₃,water and dried over magnesium sulfate. The solvent was removed underreduced pressure and the residue purified by flash chromatography(eluent:hexane/ethyl acetate 15:1) to provide 12.9 g (66%) of 1 as clearoil. ¹H NMR (360 MHz, CDCl₃) δ 1.61 (m, 4H), 2.44 (s, 3H), 2.52 (m, 2H),3.78 (s, 3H), 4.05 (m, 2H), 6.77 (d, 2H), 7.05 (d, 2H), 7.34 (d, 2H),7.78 (d, 2H).

4-(4-Methoxyphenyl)butylazide (2).

Sodium azide (3.07 g, 0.047 mol) was added to a solution of 1 (12.9 g,0.04 mol) in anhydrous DMF (70 mL) and the reaction mixture was stirred12 h at 80° C. (oil bath). Then solvent was removed at reduced pressureand the residual oil was treated with a mixture of CH₂Cl₂/ether 3:1 (100mL). The resulting solution was washed with water (2×100 mL), brine anddried over magnesium sulfate. The solvent was removed under reducedpressure and 7.6 g (95%) of 2 was obtained. The purity of 2 (99%) wasdetermined by GC and TLC (eluent:hexane/ethyl acetate 1:1), R_(f)=0.84.

4-(4-Methoxyphenyl)butylamine (3). Typical Procedure A

Lithium aluminum hydride (LAH) (55 mL of a 1.0 M solution in THF, 0.055mol) was added drop wise to a solution of 2 (7.6 g, 0.037 mol) in dryTHF (70 mL) at 0° C. The mixture was stirred overnight at roomtemperature in an argon atmosphere then the mixture was treated withwater (1.5 mL), then 15% NaOH (1.5 mL), then with more water (3 mL) andfiltered. The solid precipitate was washed with THF. The combinedorganic fractions were dried over magnesium sulfate and the solvent wasremoved under reduced pressure to give 6.2 g (94%) of 3. The purity of 3(99%) was determined by GC. ¹H NMR (360 MHz, DMSO-d₆) δ 1.34 (m, 2H),1.54 (m, 2H), 2.51 (m, 4H), 3.70 (s, 3H), 6.83 (d, 2H), 7.08 (d, 2H).¹³C (90 MHz, DMSO-d₆) δ 28.6, 330, 34.1, 41.5, 54.8, 113.1, 129.1,132.2, 157.3

4-(4-Hydroxyphenyl)butylamine hydrobromide (4). Typical Procedure BAmine 3 (2.32 g, 0.012 mol) was stirred in boiling 48% HBr (50 mL) for 3h. After the reaction was completed, argon was bubbled through thesolution and the solvent was evaporated under reduced pressure. Thesolid residue was dried above KOH to provide 3.1 g (90%) of 4. APCI MSm/z=166[C₁₀H₁₅NO+H]⁺.4-(4-Hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (5).

1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.4 g, 1.03 mmol) was added to a suspension of4-(4-hydroxyphenyl)butylamine hydrobromide (4) (0.8 g, 32 mmol) in amixture of THF (35 mL) and triethylamine (3 mL). The reaction mixturewas stirred in the boiling solvent for 3 h, then the supernatant wasseparated and the solvent was removed under reduced pressure. The oilyresidue was washed with water (2×30 mL), ether (3×30 mL) and then 10%HCl (40 mL) was added. The mixture was vigorously stirred for 10 minthen the yellow solid was filtered off, dried and recrystallized twicefrom ethanol to give 5 (0.18 g, 41%) as yellow solid. Purity is 98% byHPLC, retention time is 9.77 min. ¹H NMR (300 MHz, DMSO-d₆) δ 1.56 (brs, 4H), 2.48 (br s, 2H), 3.35 (m, 2H), 6.65 (d, 2H), 6.95 (d, 2H), 7.50(br s, 2H), 8.75 (br s, 1H), 9.05 (br s, 1H), 9.33 (br s, 2H), 10.55 (s,1H). ¹³C NMR (75 MHz, CD₃OD) 28.7, 29.8, 35.4, 42.4, 111.2, 116.1,122.0, 130.0, 134.0, 155.0, 156.1, 156.8, 157.5, 167.0. APCI MS m/z=378[C₁₆H₂₀ClN₇O₂+H]⁺.

Example 33-(4-Hydroxyphenyl)propylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

Methanesulfonic acid 3-(4-methoxyphenyl)propyl ester (11). TypicalProcedure E.

Pyridine (15 mL) was added drop wise to a cooled (0° C.) solution of4-(4-methoxyphenyl)propanol (10.0 g, 0.06 mol) and methanesulfonylchloride (14.7 g, 0.078 mol) in dry THF (70 mL) under stirring. Thereaction mixture was stirred overnight at room temperature. After thistime, the solvent was removed under reduced pressure and the residue wasquenched with 10% HCl (300 mL) and extracted with ethyl acetate. Theorganic fraction was washed with saturated NaHCO₃, water and dried oversodium sulfate. The solvent was removed and the residual crude ester 11was used in the next step without further purification. Compound 11 wasobtained as a yellow oil (8.8 g, 60%). ¹H NMR (300 MHz, CDCl₃) δ 2.08(m, 2H), 2.60 (m, 2H), 2.98 (m, 2H) 3.98 (s, 3H), 3.66 (s, 3H), 6.85 (d,2H), 7.03 (d, 2H).

3-(4-Methoxyphenyl)propylazide (12).

Azide 12 was prepared according to procedure C from 11 (8.8 g, 0.036mol) and sodium azide (3 g, 0.045 mol) in 75% yield. ¹H NMR (300 MHz,CDCl₃) δ 1.90 (m, 2H), 2.65 (t, 2H), 3.28 (m, 2H), 3.80 (s, 3H), 6.85(d, 2H), 7.10 (d, 2H).

3-(4-Methoxyphenyl)propylamine (13).

Amine 13 was prepared as described in procedure A from azide 12 (5.2 g,0.027 mol) and LAH (26 ml of 1 M solution in THF).

Crude 13 was purified by flash chromatography (silica gel, 2:1:0.05chloroform/ethanol/concentrated ammonium hydroxide) to provide pureamine 13 (3.2 g, 74%) as a clear oil. ¹H NMR (300 MHz, CDCl₃) δ 1.58 (m,2H), 2.50 (m, 4H), 3.72 (s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

3-(4-Hydroxyphenyl)propylamine hydrobromide (14).

Compound 14 was synthesized according to procedure B from 13 (2.5 g,0.015 mol) in 75% yield as a light brown solid. ¹H NMR (300 MHz,DMSO-d₆) δ 1.80 (m, 2H), 2.53 (m, 2H), 2.78 (m, 2H), 6.70 (d, 2H), 7.02(d, 2H), 7.80 (br s, 4H).

3-(4-Hydroxyphenyl)propylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (15).

Triethylamine (8 mL) was added to suspension of compound 14 (0.470 g, 2mmol) in THF (40 mL) and the mixture was stirred at room temperature for15 min. After this time1-(3,5-diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.15 g, 0.4 mmol) was added and the mixture was stirred at reflux for 3h. The solution was then cooled to room temperature and the supernatantwas isolated. The solvent was evaporated and the residual oil was washedwith ether (2×50 mL), ethyl acetate (50 mL) and treated with 20 ml of10% HCl. The obtained solid was isolated by filtration and dissolved inMeOH (approx. 50 mL). Addition of ethyl acetate (20 mL) to the solutioncaused the precipitation of a yellow solid, which was isolated bycentrifugation, washed with ethyl acetate and dried under vacuum to givecompound 15 (48 mg, 31%) as a yellow solid. ¹H NMR (300 MHz, DMSO-d₆) δ1.80 (br s, 2H), 2.58 (m, 2H), 3.95 (br s, 4H), 6.70 (d, 2H), 7.03 (d,2H), 7.48 (br. s, 2H), 8.80 (br s, 1H), 8.93 (br s, 1H), 9.32 (br s,2H), 10.52 (s, 1H). APCI MS m/z=364 [C₁₅H₁₈ClN₇O₂+H]⁺.

Example 45-(4-Hydroxyphenyl)pentylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

5-(4-Methoxyphenyl)pent-4-yn-1-ol (16).

4-Iodoanisol (10 g, 42 mmol), palladium (II) chloride (0.2 g, 1.1 mmol)and triphenylphosphine (0.6 g, 2.2 mmol) were dissolved in diethylamine(100 mL) then cupper(I) iodide (0.5 g, 2.2 mmol) and 4-pentyn-1-ol (5mL, 53 mmol) were added. The reaction mixture was stirred overnight atroom temperature, then the solvent was removed under reduced pressure.Ethyl acetate (150 mL) was added to the residue and the mixture waswashed with 2N HCl, brine and water. The organic fraction was isolated,dried with sodium sulfate and the solvent was removed under reducedpressure. The product 16 (7.1 g. 87%) was isolated by flashchromatography (silica gel, 1:2 ethyl acetate/hexanes) as an oily yellowsolid. ¹H NMR (300 MHz, CDCl₃) δ 1.88 (m, 2H), 2.53 (m, 2H), 3.72 (s,3H), 3.74 (m, 2H), 6.83 (d, 2H), 7.45 (d, 2H).

5-(4-Methoxyphenyl)pentane-1-ol (17).

A solution of 16 (7.1 g, 37 mmol) in 150 dry ethanol (150 mL) was placedin a 0.5 L Parr flask and palladium on carbon (0.92 g, 5% wet. Pd/C) wasadded as a suspension in ethanol (25 mL). The reaction mixture wasshaken at 50 psi of hydrogen pressure at room temperature for 24 hours.After this time, the mixture was filtered through a silica gel pad andthe solvent was removed at reduced pressure. The residue was purified byflash chromatography (silica gel, 1:3 ethyl acetate/hexanes) to provide17 (6.7 g, 92%) as a clear oil. ¹H NMR (300 MHz, CDCl₃) δ 1.48 (m, 2H),1.60 (m, 4H), 2.58 (m, 2H), 3.63 (m, 2H) 3.80 (s, 3H), 6.83 (d, 2H),7.10 (d, 2H).

Methanesulfonic acid 4-(4-methoxyphenyl)pentyl ester (18).

Ester 18 was prepared following procedure E from alcohol 17 (6.7 g, 34.5mmol) and methanesulfonyl chloride (4.5 mL, 50 mmol). The crude product18 (9.0 g) was obtained as a brown oil and used in the next step withoutpurification.

5-(4-Methoxyphenyl)pentyl azide (19).

Compound 19 was synthesized according to procedure C from crude 18 (9.0g) and sodium azide (2.7 g, 40 mmol). Azide 19 (6 g, 79% from 17) wasisolated by flash chromatography (silica gel, 1:1 ethylacetate/hexanes). ¹H NMR (300 MHz, CDCl₃) δ 1.40 (m, 2H), 1.62 (m, 4H),2.56 (m, 2H), 3.35 (m, 2H) 3.80 (s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

5-(4-Methoxyphenyl)pentyl amine (20).

Amine 20 was made following procedure A from 19 (6 g, 27 mmol) and LAH(26 mL of 1.0M solution in THF) in 70% yield. ¹H NMR (300 MHz, CDCl₃) δ1.35(m, 2H), 1.48 (m, 2H) 1.61 (m, 2H), 2.55 (m, 2H), 2.70 (m, 2H) 3.80(s, 3H), 6.85 (d, 2H), 7.10 (d, 2H).

5-(4-Hydroxyphenyl)pentyl amine (21).

The HBr salt of 21 was prepared according to procedure B from amine 20(2.8 g, 14 mmol). Free amine 21 (2 g, 80%) was obtained after flashchromatography (silica gel, 6:3:0.1, chloroform/ethanol/concentratedammonium hydroxide) as a cloudy oil. ¹H NMR (300 MHz, DMSO-d₆) δ 1.28(m,2H), 1.55 (m, 2H), 1.61 (m, 2H), 2.48 (m, 2H), 2.58 (m, 2H), 6.68 (d,2H), 6.98 (d, 2H).

5-(4-Hydroxyphenyl)pentylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (22).

1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.25 g, 0.65 mmol) was added to a solution of 21 (0.6 g, 3.4 mmol) inTHF (50 mL). The reaction mixture was stirred at reflux for 2 h, thenthe solvent was removed under reduced pressure and the resulting oil waswashed with ether (2×50 mL) and treated with ethyl acetate until ayellow powder was formed. The yellow solid was dissolved in methanol (70mL) and the volume was slowly reduced until precipitation began(approximately 25 mL). The solution was cooled to 0° C. and theprecipitate was collected by centrifugation. Diluted HCl (20 mL of a 10%solution) was added and the mixture was vigorously stirred for 20 min,then the precipitate was filtered off, washed with cold water, and driedto give 22 (183 mg, 39%) as a yellow solid. ¹H NMR (300 MHz, DMSO-d₆) δ1.32 (br s, 2H), 1.55 (m, 4H), 2.45 (m, 2H), 3.29 (m, 2H), 6.68 (d, 2H),6.97 (d, 2H), 7.46 (s, 1H), 8.00 (br s, 1H), 8.83 (br s, 1H), 8.97 (brs, 1H), 9.46 (d, 2H), 10.55 (s, 1H). APCI MS m/z=392[C₁₇H₂₂ClN₇O₂+H]⁺.

Example 54-(3,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

4-(3,4-Dimethoxyphenyl)butanol (23).

4-(3,4-Dimethoxyphenyl)butyric acid (13 g, 58 mmol) was dissolved in dryTHF (150 mL) then BH₃.THF (110 mL, 1M solution, 110 mmol) was added dropwise with vigorous stirring under an argon atmosphere. The reactionmixture was then stirred overnight at room temperature. After this time,the reaction was quenched with water and 10% HCl solution at 0° C. andextracted with ethyl acetate. The organic fraction was dried with sodiumsulfate and passed through a pad of silica gel. The solvent was removedat reduced pressure to give 23 (12.0 g, 99%) as a clear oil. ¹H NMR (300MHz, CDCl₃) δ 1.62 (m, 4H), 2.0 (s, 1H), 2.62 (m, 2H), 3.65 (m, 2H),3.82 (s, 3H), 3.84 (s, 3H) 6.67–6.82 (m, 3H).

Methanesulfonic Acid 4-(3,4-dimethoxyphenyl)butyl ester (24).

Ester 24 was prepared following procedure E from alcohol 23 (12.0 g, 57mmol) and methanesulfonyl chloride (8.4 g, 74 mmol) in 78% yield. ¹H NMR(300 MHz, CDCl₃) δ 1.65 (m, 4H), 2.62 (m, 2H),3.05 (s, 3H), 3.88 (br s,6H), 4.38 (m, 2H) 6.70–6.88 (m, 3H).

4-(3,4-Dimethoxyphenyl)butyl azide (25).

Compound 25 was synthesized according to procedure C from 24 (14.1 g 51mmol) and sodium azide (4.0 g, 66 mmol) in 96% yield. ¹H NMR (300 MHz,CDCl₃) δ 1.65 (m, 4H), 2.60 (m, 2H), 3.30 (m, 2H), 3.86 (br s, 6H), 6.70(m, 2H), 6.78 (m, 1H).

4-(3,4-Dimetoxyphenyl)butyl amine (26).

Amine 26 was prepared as described in procedure A from azide 25 (11.0 g,49 mol) and LAH (26 mL of 1 M solution in THF). Crude 26 was purified byflash chromatography (silica gel, 93:7:1 chloroform/ethanol/concentratedammonium hydroxide) to give pure 26 (4.8 g, 42%) as a clear oil. ¹H NMR(300 MHz, CDCl₃) δ 1.42(m, 2H), 1.60 (m, 2H), 2.55 (m, 2H), 2.74 (m,2H), 3.82 (s, 6H), 3.84 (s, 3H), 6.70 (m, 2H), 6.78 (m, 1H).

4-(3,4-Dihydroxyphenyl)butyl amine hydrobromide (27).

Compound 27 was synthesized according to procedure B from 26 (2.5 g, 11mmol) in 62% yield as a pink solid. ¹H NMR (300 MHz, DMSO-d₆) δ 1.52 (brs, 4H), 2.40 (m, 2H), 2.78 (m, 2H), 6.42 (m, 1H), 6.60 (m, 2H), 7.80 (brs, 4H).

4-(3,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (28).

1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.2 g, 0.51 mmol) was added to a suspension of 27 in a mixture of THF(35 mL) and triethylamine (3 mL). The reaction mixture was stirred atreflux for 3 h, then the supernatant was separated and the solvent wasremoved under reduced pressure. The brown residue was washed with ether(2×30 mL) followed by addition of 10% HCl (5 mL). The solid material wascollected, dissolved in methanol and precipitated by addition of ethylacetate. The precipitate was washed with 10% HCl and dried to givecompound 28 (131 mg, 51%) as a beige solid. ¹H NMR (300 MHz, DMSO-d₆) δ1.52 (br s, 4H), 2.42 (m, 2H), 3.31 (m, 2H), 6.43 (m, 1H), 6.61 (m, 2H),7.42 (br s, 2H), 7.90 (br s, 1H), 8.82 (br s, 1H), 8.98 (br s, 1H), 9.25(s, 1H) 10.52 (s, 1H). APCI MS m/z=394 [C₁₆H₂₀ClN₇O₃+H]⁺.

Example 64-(4-Hydroxyphenyl)-4-oxabutylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrobromide

4-(4-Hydroxyphenyl)-4-oxabutylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrobromide (63).

The vigorously stirred solution of 62 (80 mg, 0.19 mmol) in 48% HBr (15mL) was refluxed 2 h and then cooled. The precipitate that formed wasseparated, washed with water and dried overnight to provide 63 (52 mg,52%). ¹H NMR (300 MHz, DMSO-d₆) δ 1.99 (m, 2H), 3.96 (m, 2H), 6.77 (m,2H), 6.79 (m, 2H), 7.45 (s, 2H), 8.74 (br s, 1H), 8.87 (br s, 1H), 9.30(s, 1H) 10.48 (s, 1H). APCI MS m/z 380 [C₁₅H₁₈ClN₇O₃+H]⁺.

Example 7

4-(2,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride

4-(2,4-Dimethoxyphenyl)-but-3-yn-1-ol (75).

1-Bromo-2,4-dimethoxybenzene (10 g 0.046 mol), palladium chloride (0.2 g0.11 mmol) and triphenylphosphine (0.6 g 0.0023 mol) were dissolved indiethylamine (100 mL) under a nitrogen atmosphere. Copper (I) iodide(0.44 g 0.0023 mol) and 3-butyn-1-ol (7 mL 0.092 mol) were added intothe reaction mixture at once. The mixture was stirred overnight at 55°C. under a nitrogen atmosphere. The catalyst was filtered off from thereaction mixture and the same amount of palladium chloride,triphenylphosphine, copper (I) iodide and 3-butyn-1-ol were added. Thereaction mixture was stirred and heated at 85° C. for 48 hours. Then thesolvent was removed at reduced pressure and water (approx. 100 mL) wasadded to the residue. The mixture was extracted with ethyl acetate (350mL) passed through a pad of silica gel and concentrated. The product waspurified by flash chromatography (silica gel, 1:1 hexanes/ethylacetate). Compound 75 (4.2 g, 24%) was isolated as a brown oil. ¹H NMR(300 MHz, CDCl₃) δ 2.24 (t, 1H), 2.73 (t, 2H), 3.80 (br s, 5H), 3.87 (s,3H), 6.43 (m, 2H), 7.30 (m, 1 H).

4-(2,4-Dimethoxyphenyl)-butan-1-ol (76).

To a solution of 75 (4.2 g, 0.022 mol) in ethanol (approx. 200 mL) wasadded palladium (5% wet on activated carbon, 1 g). Then the mixture washydrogenated at 40 psi overnight at room temperature. The mixture wasfiltered through a pad of silica gel and the solvent was evaporated togive 76 (4.15 g, 97%) as a yellow oil. ¹H NMR (300 MHz, CDCl₃) δ 1.59(m, 4H), 2.55 (m, 2H), 3.79 (s, 6H), 6.43 (m, 2H), 7.00 (m, 1H).

Methanesulfonic acid 4-(2,4-dimethoxyphenyl)butyl ester (77).

Ester 77 was prepared by typical procedure E from alcohol 76 (4.15 g,0.021 mol), methanesulfonyl chloride (2.4 mL, 0.03 mol) andtriethylamine (20 mL). Crude 77 (4.6 g, 80%) was isolated as a yellowoil

4-(2,4-Dimethoxyphenyl)butyl azide (78).

Azide 78 was prepared by typical procedure C from ester 77 (4.6 g, 0.015mol) and sodium azide (1.5 g, 0.023 mol). Compound 77 (4.06 g, 75%) wasisolated as a yellow oil. ¹H NMR (300 MHz, CDCl₃) δ 1.62 (m, 4H), 2.58(m, 2H), 3.30 (m, 2H), 3.80 (s, 6H), 6.43 (m, 2H), 7.00 (m, 1H).

4-(2,4-Dimethoxyphenyl)butyl amine (79).

Amine 79 was prepared by typical procedure A from azide 78 (4.06 g,0.017 mol) and LiAlH₄ (13 mL of a 1.0 M solution in THF). The materialwas purified by column chromatography (silica gel, 2:1:0.1chloroform/ethanol/concentrated ammonium hydroxide) to provide 79 (2.3g, 64%) as a white solid. ¹H NMR (300 MHz, CDCl₃) δ 1.53 (m, 4H), 2.53(m, 2H), 2.73 (m, 2H), 3.80 (s, 6H), 6.43 (m, 2H), 7.52 (m, 1H).

4-(2,4-Dimethoxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (80).

1-(3,5-Diamino-6-chloropyrazinoyl-2-methyl-pseudothiourea hydroiodide(0.3 g, 0.77 mmol) was added to an anhydrous THF solution (30 mL) of 79(0.4 g, 1.9 mmol). The reaction mixture was stirred at reflux for 3 hthen the solvent was evaporated. The residue was washed with ethylacetate (2×20 mL) then treated with 3% HCl (15 mL). The yellow solidthat formed was separated, washed with water and dried overnight toprovide compound 80 (0.32 g, 90%). ¹H NMR (300 MHz, DMSO-d₆) δ 1.57 (s,4H), 2.50 (br s, 2H), 3.35 (br s, 2H), 3.73 (s, 3H), 3.76 (s, 3H), 6.43(m, 1H), 6.52 (s, 1H), 7.02 (m, 1H), 7.45 (br s, 2H), 8.86 (br s, 1H),8.99 (br s, 1H), 9.03 (m, 1H), 10.56 (s, 1H). APCI MS m/z 422[C₁₈H₂₄ClN₇O₃+H]⁺.

4-(2,4-Dihydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride (81).

A vigorously stirred solution of 80 (290 mg, 0.63 mmol) in 48% HBr (20mL) was refluxed for 4 h and then cooled. The solvent was removed atreduced pressure and the material was purified by column chromatography(silica gel, 4:1:0.1 chloroform/ethanol/concentrated ammoniumhydroxide). The fractions with product were collected and the solventwas removed under reduced pressure. The residue was treated with 3% HCl,washed with water (2×5 mL) and dried to provide 81 (79 mg, 32%) as ayellow solid. ¹H NMR (300 MHz, DMSO-d₆) δ 1.54 (s, 4H), 2.43 (br s, 2H),3.31 (br s, 2H), 6.12 (d, 1H), 6.32 (s, 1H), 6.78 (d, 1H), 8.86 (br s,1H), 8.99 (br s, 1H), 9.28 (s, 1H), 10.56 (s, 1H). APCI MS m/z 394[C₁₆H₂₀ClN₇O₃+H]⁺.

REFERENCES

-   1. Taylor, E. C.; Harrington, P. M.; Schin,C. Heterocycles, 1989,    28, 1169-   2. Widsheis et al, Synthesis, 1994, 87–92

Example 8 Sodium Channel Blocking Activity

The compounds shown in Tables 1–5 below were tested for potency incanine bronchial epithelia using the in vitro assay described above.Amiloride was also tested in this assay as a positive control. Theresults for the compounds of the present invention are reported asfold-enhancement values relative to amiloride.

TABLE 1

Fold Enhancement Position R Over Amiloride 2,4 H 14.9 3,5 H 13.7 3,4 H15.1 2,5 H 20.3

TABLE 2

Position Fold Enhancement n of R R Over Amiloride 5 4 OH 14 3 4 OH 5.2 44 OH 50.3

TABLE 3

Fold Enhancement Q R Over Amiloride N OH 9.5 CH OH 50.3

TABLE 4

Fold Enhancement a b R Over Amiloride CH₂ O H 16.1

Example 9 Effect of4-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V) on MCC

This experiment was conducted with4-(4-hydroxyphenyl)butylamidino-3,5-diamino-6-chloropyrazinecarboxamidehydrochloride (V), and the vehicle as a control. The results are shownin FIGS. 1 and 2.

Methods

Animal Preparation: The Mount Sinai Animal Research Committee approvedall procedures for the in vivo assessment of mucociliary clearance.Adult ewes (ranging in weight from 25 to 35 kg) were restrained in anupright position in a specialized body harness adapted to a modifiedshopping cart. The animals' heads were immobilized and local anesthesiaof the nasal passage was induced with 2% lidocaine. The animals werethen nasally intubated with a 7.5 mm internal diameter endotracheal tube(ETT). The cuff of the ETT was placed just below the vocal cords and itsposition was verified with a flexible bronchoscope. After intubation theanimals were allowed to equilibrate for approximately 20 minutes priorto initiating measurements of mucociliary clearance.

Administration of Radio-aerosol: Aerosols of ^(99m)Tc-Human serumalbumin (3.1 mg/ml; containing approximately 20 mCi) were generatedusing a Raindrop Nebulizer which produces a droplet with a medianaerodynamic diameter of 3.6 μm. The nebulizer was connected to adosimetry system consisting of a solenoid valve and a source ofcompressed air (20 psi). The output of the nebulizer was directed into aplastic T connector; one end of which was connected to the endotrachealtube, the other was connected to a piston respirator. The system wasactivated for one second at the onset of the respirator's inspiratorycycle. The respirator was set at a tidal volume of 500 mL, aninspiratory to expiratory ratio of 1:1, and at a rate of 20 breaths perminute to maximize the central airway deposition. The sheep breathed theradio-labeled aerosol for 5 minutes. A gamma camera was used to measurethe clearance of ^(99m)Tc-Human serum albumin from the airways. Thecamera was positioned above the animal's back with the sheep in anatural upright position supported in a cart so that the field of imagewas perpendicular to the animal's spinal cord. External radio-labeledmarkers were placed on the sheep to ensure proper alignment under thegamma camera. All images were stored in a computer integrated with thegamma camera. A region of interest was traced over the imagecorresponding to the right lung of the sheep and the counts wererecorded. The counts were corrected for decay and expressed aspercentage of radioactivity present in the initial baseline image. Theleft lung was excluded from the analysis because its outlines aresuperimposed over the stomach and counts can be swallowed radio-labeledmucus.

Treatment Protocol (Assessment of activity at t-zero): A baselinedeposition image was obtained immediately after radio-aerosoladministration. At time zero, after acquisition of the baseline image,vehicle control (distilled water), positive control (amiloride), orexperimental compounds were aerosolized from a 4 ml volume using a PariLC JetPlus nebulizer to free-breathing animals. The nebulizer was drivenby compressed air with a flow of 8 liters per minute. The time todeliver the solution was 10 to 12 minutes. Animals were extubatedimmediately following delivery of the total dose in order to preventfalse elevations in counts caused by aspiration of excess radio-tracerfrom the ETT. Serial images of the lung were obtained at 15-minuteintervals during the first 2 hours after dosing and hourly for the next6 hours after dosing for a total observation period of 8 hours. Awashout period of at least 7 days separated dosing sessions withdifferent experimental agents.

Treatment Protocol (Assessment of Activity at t-4hours): The followingvariation of the standard protocol was used to assess the durability ofresponse following a single exposure to vehicle control (distilledwater), positive control compounds (amiloride or benzamil), orinvestigational agents. At time zero, vehicle control (distilled water),positive control (amiloride), or investigational compounds wereaerosolized from a 4 ml volume using a Pari LC JetPlus nebulizer tofree-breathing animals. The nebulizer was driven by compressed air witha flow of 8 liters per minute. The time to deliver the solution was 10to 12 minutes. Animals were restrained in an upright position in aspecialized body harness for 4 hours. At the end of the 4-hour periodanimals received a single dose of aerosolized ^(99m)Tc-Human serumalbumin (3.1 mg/ml; containing approximately 20 mCi) from a RaindropNebulizer. Animals were extubated immediately following delivery of thetotal dose of radio-tracer. A baseline deposition image was obtainedimmediately after radio-aerosol administration.

Serial images of the lung were obtained at 15-minute intervals duringthe first 2 hours after administration of the radio-tracer (representinghours 4 through 6 after drug administration) and hourly for the next 2hours after dosing for a total observation period of 4 hours. A washoutperiod of at least 7 days separated dosing sessions with differentexperimental agents.

Statistics: Data were analyzed using SYSTAT for Windows, version 5. Datawere analyzed using a two-way repeated ANOVA (to assess over effects),followed by a paried t-test to identify differences between specificpairs. Significance was accepted when P was less than or equal to 0.05.Slope values (calculated from data collected during the initial 45minutes after dosing in the t-zero assessment) for mean MCC curves werecalculated using linear least square regression to assess differences inthe initial rates during the rapid clearance phase.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

All of the references cited above are incorporated herein by reference.

1. A compound represented by formula (I):

wherein X is hydrogen, halogen, trifluoromethyl, lower alkyl,unsubstituted or substituted phenyl, lower alkyl-thio, phenyl-loweralkyl-thio, lower alkyl-sulfonyl, or phenyl-lower alkyl-sulfonyl; Y ishydrogen, hydroxyl, mercapto, lower alkoxy, lower alkyl-thio, halogen,lower alkyl, unsubstituted or substituted mononuclear aryl, or—N(R²)₂;R¹ is hydrogen or lower alkyl; each R² is, independently, —R⁷,—(CH₂)_(m)—OR⁸, —(CH₂)_(m)—NR⁷R¹⁰, —(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—(CH₂)_(n)—Z_(g)—R⁷, —(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—(CH₂)_(n)—CO₂R⁷, or

R³ and R⁴ are each, independently, hydrogen, a group represented byformula (A), lower alkyl, hydroxy lower alkyl, phenyl, phenyl-loweralkyl, (halophenyl)-lower alkyl, lower-(alkylphenylalkyl), loweralkoxyphenyl)-lower alkyl, naphthyl-lower alkyl, or pyridyl-lower alkyl,with the proviso that at least one of R³ and R⁴ is a group representedby formula (A):

wherein each R^(L) is, independently, —R⁷, —(CH₂)_(n)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸) (CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸,—O—(CH₂CH₂O)_(m)—R⁸, —(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —(CH₂)_(n)—C(═O)NR⁷R¹⁰,—O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)—(Z)_(g)—R⁷,—O—(CH₂)_(m)—(Z)_(g)—R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m)—CO₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose, or

each x is, independently, O, NR⁷, C═O, CHOH, C═N—R⁶, or represents asingle bond; each o is, independently, an integer from 0 to 10; each pis, independently, an integer from 0 to 10; with the proviso that (a)the sum of o and p in each contiguous chain is from 1 to 10 when x is O,NR⁷, C═O, or C═N—R⁶ or (b) that the sum of o and p in each contiguouschain is from 4 to 10 when x represents a single bond; each R⁶ is,independently, —R⁷, —OH, —OR¹¹, —N(R⁷)₂, —(CH₂)_(m)—OR⁸,—O—(CH₂)_(m)—OR⁸, —(CH₂)_(n)—NR⁷R¹⁰, —O—(CH₂)_(m)—NR⁷R¹⁰,—(CH₂)_(n)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —O—(CH₂)_(m)(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂CH₂O)_(m)—R⁸, —O—(CH₂CH₂O)_(m)—R⁸,—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰, —O—(CH₂CH₂O)_(m)—CH₂CH₂NR⁷R¹⁰,—(CH₂)_(n)—C(═O)NR⁷R¹⁰, —O—(CH₂)_(m)—C(═O)NR⁷R¹⁰, —(CH₂)_(n)—(Z)_(g)—R⁷,—O—(CH₂) _(m)—(Z)_(g)—R⁷, —(CH₂)_(n)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸,—O—(CH₂)_(m)—NR¹⁰—CH₂(CHOR⁸)(CHOR⁸)_(n)—CH₂OR⁸, —(CH₂)_(n)—CO₂R⁷,—O—(CH₂)_(m—CO) ₂R⁷, —OSO₃H, —O-glucuronide, —O-glucose,

wherein when two R⁶ are —OR¹¹ and are located adjacent to each other ona phenyl ring, the alkyl moieties of the two R⁶ may be bonded togetherto form a methylenedioxy group; each R⁷ is, independently, hydrogen orlower alkyl; each R⁸ is, independently, hydrogen, lower alkyl,—C(═O)—R¹¹, glucuronide, 2-tetrahydropyranyl, or

each R⁹ is, independently, —CO₂R⁷, —CON(R⁷)₂, —SO₂CH₃, or —C(═O)R⁷; eachR¹⁰ is, independently, —H, —SO₂CH₃,—CO₂R⁷, —C(═O)NR⁷R⁹, —C(═O)R⁷, or—CH₂—(CHOH)_(n)—CH₂OH; each Z is, independently, CHOH, C(═O), CHNR⁷R¹⁰,C═NR¹⁰,or NR¹⁰; each R¹¹ is, independently, lower alkyl; each g is,independently, an integer from 1 to 6; each m is, independently, aninteger from 1 to 7; each n is, independently, an integer from 0 to 7;each Q is, independently, C—R⁶ or a nitrogen atom, wherein three Q in aring are nitrogen atoms; or a pharmaceutically acceptable salt thereof,and inclusive of all enantiomers, diastereomers, and racemic mixturesthereof.
 2. The compound of claim 1, wherein Y is —NH₂.
 3. The compoundof claim 2, wherein R² is hydrogen.
 4. The compound of claim 3, whereinR¹ is hydrogen.
 5. The compound of claim 4, wherein X is chlorine. 6.The compound of claim 5, wherein R³ is hydrogen.
 7. The compound ofclaim 6, wherein each R^(L) is hydrogen.
 8. The compound of claim 7,wherein o is
 4. 9. The compound of claim 8, wherein p is
 0. 10. Thecompound of claim 9, wherein x represents a single bond.
 11. Thecompound of claim 10, wherein each R⁶ is hydrogen.
 12. The compound ofclaim 11, wherein X is halogen; Y is —N(R⁷)₂; R¹ is hydrogen or C₁–C₃alkyl; R² is —R⁷, —(CH₂)_(m)—OR⁷, or —(CH₂)_(n)—CO₂R⁷; R³ is a grouprepresented by formula (A); and R⁴ is hydrogen, a group represented byformula (A), or lower alkyl.
 13. The compound of claim 12, wherein X ischloro or bromo; Y is —N(R⁷)₂; R² is hydrogen or C₁–C₃ alkyl; at mostthree R⁶ are other than hydrogen as defined above; and at most threeR^(L) are other than hydrogen as defined above.
 14. The compound ofclaim 13, wherein Y is —NH₂.
 15. The compound of claim 14, wherein R⁴ ishydrogen; at most one R^(L) is other than hydrogen as defined above; andat most two R⁶ are other than hydrogen as defined above.
 16. Thecompound of claim 15, wherein x is O, NR⁷, C═O, CHOH, or C═N—R⁶.
 17. Thecompound of claim 15, wherein x represents a single bond.
 18. Thecompound of claim 1, wherein x is O, NR⁷, C═O, CHOH, or C═N—R⁶.
 19. Thecompound of claim 1, wherein x represents a single bond.
 20. Thecompound of claim 1, wherein each R⁶ is hydrogen.
 21. The compound ofclaim 1, wherein at most two R⁶ are other than hydrogen as defined inclaim
 1. 22. The compound of claim 1, wherein one R⁶ is other thanhydrogen as defined in claim
 1. 23. The compound of claim 1, wherein oneR⁶ is —OH.
 24. The compound of claim 1, wherein each R^(L) is hydrogen.25. The compound of claim 1, wherein at most two R^(L) are other thanhydrogen as defined in claim
 1. 26. The compound of claim 1, wherein oneR^(L) is other than hydrogen as defined in claim
 1. 27. The compound ofclaim 1, wherein x represents a single bond and the sum of o and p is 4to
 6. 28. The compound of claim 1, which is in the form of apharmaceutically acceptable salt.
 29. The compound of claim 1, which isin the form of a hydrochloride salt.
 30. The compound of claim 1, whichis in the form of a mesylate salt.
 31. A pharmaceutical composition,comprising the compound of claim 1 and a pharmaceutically acceptablecarrier.
 32. A composition, comprising: the compound of claim 1; and aP2Y2 receptor agonist.
 33. A composition, comprising: the compound ofclaim 1; and a bronchodilator.
 34. A method of blocking sodium channels,comprising contacting sodium channels with an effective amount of thecompound of claim 1.